Public service announcements (PSA) have been utilized successfully to promote the health behaviors to the public. In spite that Hong Kong government keep increasing the budget of PSA (admanGo, 2015;2016), the effectiveness of PSA is seldom measured. Previous studies focus on testing the discourses, contents, and public's interpretations of PSA (Chan and Huang, 2015; Chan & Chang, 2013; Wong, 2006). Little research tries to explore the design and effectiveness of PSA. Besides, Hong Kong is facing a serious road safety issue due to the rapid development of the economy. And the convenient use of mobile phones causes the public pays less attention to road safety issue. According to the annual report of road safety council (2015), "inattentively" is the primary contributory factor in road accidents both from driver perspective and passenger perspective. A study was designed to investigate the public attitudes and behavior related to road safety and their responses to public service announcements using narrative or fear appeals. Two main theories were utilized to create the theoretical framework for this study: Regulatory fit theory and the Theory of planned behavior. The hedonic principle plays a role in the basic function of RFT and TPB. Both of them aim to change people's behavioral intentions and concerns that people approach pleasure and avoid pain. The core principle in RFT is to examine people's approach and avoidance mechanisms based on the two regulatory focus systems. On the other hand, TPB emphasizes that people's intentions are performed based on the chronic perceptions of the positive or negative outcomes of the recommended behaviors. Once people think the recommended behaviors are favorable, they are more likely to engage, which matches the principle of pleasant and pain from RFT. This study investigates the impact of either focusing on promotion or prevention in the Regulatory fit theory along with fear appeal, which could modify the variables in Theory of planned behavior, by taking road safety as a context. The purpose of this study is to explore whether Regulatory fit theory with fear framing will have merit under several conditions that may influence individuals' emotional responses, behavioral intentions, and information processing. Survey methodology was adopted. A model incorporating variables in RFT and TPB was proposed. A structured questionnaire was designed to include the key constructs in the RFT and TPB. Altogether 523 responses were collected from 30 November 2017 to 24 December 2017, including 106 respondents from the questionnaire in paper form and 481 from the online platform, in Hong Kong and Mainland China. Four types of stimuli were designed to examine the model. Empirical data of this study confirms the high influence of predictors including attitude towards behavior, perceived behavioral control, and subjective norms to predict behavior intention. In particular, subjective norms are the highest-level predictor. About the self-regulatory fit, promotion focus predicts more than prevention focus on health communication. What's more, the results showed that perceived relevance is a key factor when people make decisions about a health-related behavior. This study theoretically attempts to extend Regulatory fit theory by adding fear as the emotional variable that tests whether fear is fit/unfit for an individual's regulatory focus, especially in the behavioral health context, which can help practitioners better understand the use of fear appeal along with Regulatory fit theory and how it impacts individuals' health behaviors. Practically, this study explores the theory-driven communication strategy for practitioners. Fear appeal is one of the most common tactics in health communication campaigns, but there is a lack of research to compare the practical impact of fear appeal. For instance, most practitioners prefer to adopt fear appeal rather than emotional appeals or narrative appeals in health promotions, but few empirical studies have verified the benefits of fear appeal from a theory-based perspective. Furthermore, this study seeks to answer some questions in daily health communication in daily life by applying the Regulatory fit theory, such as how different focus-oriented people understand the fear appeals in health messages. The findings of this study will explore some effective message strategies for health communications and marketing practitioners.